Decalcomania paper



Jan. 4, 1938. DAVIS 2,104,025 I DECALCOMANIA PAPER Filed Aug. 25. 1934 /N l/ENTOR KM a ATTORNEV Patented Jan. 4, 193a QECALGOMANIA PAPER Lewis Davis, Worcester, Mass., assignor to Mc-' Laurin-J'ones 00., Brookfleld, Mass., :1. corporation of Massachusetts Application August 23, 1934, serial-No. 141,121

9 Claims.

This invention relates to decalcomanias and is .more especially concerned with the papers on which'decalcomania designs are printed.

In applying such designs to some articles of 6 work, such as water absorbent bodies and especially wood veneers, the use of the necessary quantity of water required to separate the backing sheet from the decalcomania film is highly.-ob-' jectionable because it tends to warp theveneer 10 and make it diificult to properly register or abut the edges of adjoining .sheets. If, in addition, the veneer is to be applied to a body or core made of wood, or some other water absorbent material, which usually is the case, then the application i 15 of water is even more objectionable. This factor becomes especially important in applying such designs to large surfaces such, for example, as wood paneling.

' The present invention deals with the problem presented by these conditions and it aims to devise a decalcomania paper which will avoid these objections.

The'nature of the invention will be readily un*' derstood from the following description when read 25 in connection with the accompanying drawing,

and the novel features will be particularly pointed out in the appended claims.

In the drawing, v Figure 1 is a perspective view of a portion of a 30 sheet of decalcomania paper embodying features of this invention; and I Fig. 2 is-a vertioaLsectional view on a large scale of a portion of the sheet shown in Fig. l.

The product shown inthe drawing comprises 35 a backing sheet I of paper carrying on one face thereof two superposed coats of waterproof material, (the term "waterproof being used in its common, rather than its strictly scientific, sense) the respective coats being designated at 2 and I. 40 This sheet may be of any suitable character, such,

for example, as the, unsized' backing papers commonly used heretofore in decalcomania papers, but in any event should be readily penetrable by the releasing solvent. The upper or outer coat 45 3 should have a smooth, uniform surface adapted to takedecalcomania printing, while the under coat 2 acts both'as a sizing to prevent the penetration of the upper coating material into the backing sheet during the manufacturing opera- 6 0 tions, and serves also to bond the outer coat to the backing sheet. A further-highly desirable property in this under coat ls that it shall possess a'high degree of fslip when wet with the releasing liquid or solvent in order to facilitate as the separation of the decalcomania film from the V (01. 41-33) v backing sheet I.

For some purposesit is-desirable also to have coatings differentially soluble the other is highly re portant for most purposes other words, to a solvent to which But it is also imthat both coats be 'sistant.

readilysoluble in some non-aqueous solvent which is inexpensive, is readily obtainable, and which,

therefore, can be used in effecting the release of the decalcomania film. a 10 I have found that the foregoing requirements can be satisfied by making the outer coatof a resinous nature and the under coat of a rubbery character. The best" material which I have so far discovered for the outer coat 3 is the synthetic resin For the under coat I known commercially as Cumar.

prefer to use rubber latex,

although various other rubber compositions can proportion of glue order to increase material and thus the backing sheet. A

the

parts, water 40 parts,

be employed satisfactorily. v

According tothe preferred method, a small is added to. the rubber latex in adhesive properties of this to produce a better bond with typical formula consists of rubber latex (having 2% and ammonia 1 part. 'All of the'seproportions are by weight. A satisfactory casein glue mixture may be made by .dis-

solving one part of caseinin four parts of water and using any suitable alkali in a proportion of about 15% of the weight of the casein to assist indissolving the latter ingredient. Other adhesives such as animal or fish glue,

c and the like, can be substituted for the casein.

The application of the glue and latex mixture to the paper may conveniently be made-in the usual coating machinery. For most purposes-an extremely thin coat only is to two pounds of solid required, say from one 40 constituents Y to a ream of paper, the sheets-measuring 20 x 24 inches. The

thickness of this coating. to suit therequirements by suitably corftrolling mixture. As above st sizing to prevent the coating into the backing sheet. I

After the first coat has to dry it is calendered however, can be varied of individual situations the 'consistenc'y f the ated, this coating acts as a penetration of the second been applied and then the outer 'cumar s0 coat is put on. Cumar is known chemically as a coumarone-indene r esin and may be defined as a mixture of para-coumarone, para-indene and the polymers of. coal tar. It is a neutr other hydrocarbons found in 9.1 resin produced from coal gum arable, 35

andalldwed tar distillates and is soluble in a considerable variety of common solvents such as gasolene and other petroleum distillates, carbon tetrachloride, ethyl and amyl acetates, and others. In preparing this coating material for application to the backing sheet, it should be borne in mind that the outer coating 3 must be very fiat, smooth, and free from imperfections since the decalcomania design will be printed on this surface. For this reason it is desirable to associate suitable plasticizers with the Cumar resin and thesolvents for it in order to produce a coating of the desired smoothness. Since the least expensive of the solvents for the Cumar consists of a. petroleum distillate, it is ordinarily preferable to use this material. Assuming that in the final product the Cumar coat is to weigh four pounds to the ream, with sheets of the size above mentioned, a suitable composition may be composed of the following ingredients;

, Grams Cumar 814 Ethyl acetate 424 Butyl Cellosolve.. 12 Dibutyl phthalate 48.5 Troluoil 725 Of these constituents the chief solvent is the Troluoil which is a petroleum distillate having a boiling range of from' about 99 C. to 116 C. Other petroleum fractions, however, can be substituted for it. The ethyl acetate is a solvent aid. The dibutyl phthalate is a plasticizer, and the Butyl Cellosolve (ethylene glycol monobutyl ether) performs similar functions, acting as a leveling agent. The latter may. however, be omitted. This composition produces a very smooth satisfactory coating.

The paper so prepared is shipped to the decalcomania manufacturer who prints his design on the surface, of the outer coat 3. The decalcomania so produced may be either of the ordinary transfer type or of the so-called "slide oil! variety. After it has been applied to the work it is freed or released fromthe backing sheet by applying gasolene or some-other suitable solvent to the surface of the backing paper, this solvent penetratingthe paper readily and acting rapidly on the latex rubber under coat. As above stated. this coating is very thin audit is of a somewhat porous or spongy nature so that the gasolene quickly penetrates through it and acts on the rubber particles to dissolve, or at least to soften, them. That part of the gasolene which permeates the rubber coating also acts on the Cumar coat and begins to dissolve it. This action proceeds very rapidly so that in a matter of fifteen or twenty seconds the decalcomania film is freed from the backing sheet and can either be slid off or the backing sheet can be peeled oil. In either event a clean separation of the backing sheet is produced. It is not strictly correct from a scientific standpoint to say that the rubber particles are dissolved by gasolene, although whether or not this is the fact is not material so far as this invention is concerned. The gasolene, however, does penetrate the rubber coat, it swellsthe rubber particles, and so far softens or dissolves this and the Cumar coat that the union of the, Cumar ,coat with the backing sheet is substantially destroyed and a high degree of slip or lubrication is produced in place of the adhesion which formerly existed. In addition, the separation of the decalcomania film from the backing sheet is greatly facilitated by the swellare printed on this surface. practice to apply a coating of clear lacquer over .used in such a lacquer.

ing of the rubber particles in the under coating, which has the effect of pushing the film and the backing away from each otlfer.

' In'making the Cumar composition it is pref-' erable to use the hardest grade of this resin and to make a solution of a fairly high concentration, say 60%. gum, can be used instead of part or all of the Cumar, although I have not found it as satisfactory as the latter. By ester gum I mean the compound that also goes under the name of rosin ester or glycerinated rosin. Araclor resin,

whether vulcanized or unvulcanized, is definitely superior for the purposes of this invention to milled rubber. i

An important advantage of the product above described is that the outer coat is not substantially affected by the more common solvents used in the inks with which the decalcomania designs Also, it is a common a decalcomania design, and the Cumar resin coat is highly resistant to the solvents commonly In applying decalcomanias of this type to .veneer and other water absorbing bodies, some In some cases decalcomania manufacturers prefer to use an ink which, from a chemical point of view, is really a varnish or paint and includes a vegetable oil, or some other constituent which will attack the Cumar coat. When such an ink is to be used I prefer either to substitute for the outer Cumar coatkor to cover it with, an outside coat of some" material which will not Other gums, however, such as ester be affected by an ink of this kind. For this purpose a coating material made of gum sandarac and rosin may be used, the composition consisting of approximately seven parts, by weight, of gum sandarac to ten parts of rosin (colophony), or shellac, dissolved in about nine parts ofIdenatured alcohol as, for example, Formula No. 5

prescribed by the U. S. Internal Revenue Bureau.

said backing sheet.

1. A decalcomania paper comprising a suitable backing sheet, an outerwaterproof coating carried-by said sheet to take decalcomania printing, and a protective coating of a rubbery nature between the first mentioned coating and said sheet.

2. A decalcomania paper comprising a suitable backing sheet, an outer waterproof coating I carried by said sheet to take decalcomania printing, and an intermediate coating of a rubbery nature bonding the first mentioned coating to 3. A decalcomania paper comprising a'suitable backing sheet, and a plurality of coatings of waterproof material in superposed relationship on one face of said sheet, said coatings having radically different characteristics, the outermost of said coatings being adapted to take decal comania printing and; one of the coatings being of a rubbery nature.

4. A decalcomania paper comprising a suitable backing sheet, an outer waterproof coating of a resinous nature carried by said sheet to take decalcomania printing, and an intermediate coating of a rubbery nature bonding the first men tioned coating to said backing sheet.

5. A decalcomania paper comprising a suitable backing sheet, an outer waterproof coating of a resinous nature carried by said sheet to take decalcomania printing, and an intermediate coating consisting chiefly of latex rubber bonding the first mentioned coating to said backing sheet.

6. A decalcomania paper comprising a suitable backing sheet, an outer waterproof coating carried by said sheet to take decalcomania printing,

the predominating constituent of said coatingbeing coumarone-indene resin, and an intermediate waterproof coating bonding the first mentioned coating'tosaid backing sheet, the predominating constituent of said intermediate'coating being latex rubber.-

7. A decalcomania paper comprising a suitable backing sheet, an outer waterproof coating carried by said sheet and adapted to take decal comania printing, said coating being highly resistant to the common solvents used in printing ink, an under waterproof coating of a resinous nature bonded to said outer coating and a third waterproof coating bonding said under coating to said sheet, said third coating containing a subof the coatings being of a rubbery nature, said backing sheet being pervious to a liquid solvent for one of said coatings.

9. A decalcomania paper comprising a suitable backing sheet, an outer waterproof coating carried by said sheet adapted to take decalcomania printing, and a plurality of additional coatings between said outer coating and said sheet and bonding the outer coating to the backing sheet, said intermediate coatings having radically different characteristics and one of them being of a rubbery nature, said backing" sheet being pervious to a liquid solvent for one of said intermediate coatings.

LEWIS DAVIS. 

